Leak detector

ABSTRACT

A leak detector assembly for use with a backflow prevention device includes a housing defining a passageway for receiving a fluid. A flap assembly couples to the housing for generating a low flow error signal indicating minimal fluid passing through the passageway and a fully actuated error signal indicating significant fluid passing through the passageway. The flap assembly includes a flap mounted in the passageway such that significant flow of the fluid moves the flap to generate the fully actuated error signal. The flap assembly also includes a sensing element on the flap to determine a presence of the fluid without movement of the flap to generate the low flow error signal based on a low flow of the fluid.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Patent ApplicationNo. 62/311,761, filed Mar. 22, 2016, which is incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The subject disclosure relates to leak detectors, and more particularlyto leak detectors for backflow prevention devices in water systems.

2. Background of the Related Art

Generally, backflow is any unwanted reversal of the flow of liquids,solids, or gases in a piping system such as a fire protection system.For another example, backflow in an irrigation application is when waterfrom the sprinkler system travels “upstream” through the pipes andenters the potable water system through a cross-connection. Across-connection is any connection between a potable (drinkable) watersystem and any system containing non-potable water, pollutants, ortoxins. An example of where a cross-connection would exist is when ahome's external tap has a hose connected that runs into a pool, which iselevated above the home's water tank.

Backpressure can also create undesirable contamination. Backpressure iswhen the pressure downstream of the backflow devices exceeds the supply(or upstream) pressure. Backpressure can occur if the supply pressure isreduced, or if the pressure downstream is increased. Back siphonage canalso create contamination. Back siphonage occurs when a vacuum iscreated upstream of the backflow device, and water is literally suckedback up the system. Back siphonage can happen when the water supply isstopped due to a water main break or nearby fire hydrant use.

In view of the above, many types of backflow prevention devices havebeen designed to prevent contaminants from entering potable watersystems. Backflow prevention devices are used in all types of premises,whether industrial, commercial or residential. Backflow preventiondevices help protect the public safety by preventing potable watercontamination in such critical areas as municipal water systems, foodprocessing plants, medical and dental water supplies, and manyindustrial applications. The Safe Drinking Water Act, signed into law in1974, placed the responsibility of local governments and waterauthorities for drinking water protection to promote public health andsafety. As a result, most building codes and prudent designers requirebackflow prevention devices.

There are multiple types of backflow prevention devices or back flowpreventers, the three most common being the pressure vacuum breaker(PVB), the reduced pressure zone (RPZ), and the double check assembly(DCA). These are all installed in the water system immediately after theisolation valve. There is a fourth backflow preventer which is alsofairly common; the atmospheric vacuum breaker (AVB), which is installedon each zone of the sprinkler system, immediately after the zone controlvalve. Each type of backflow device is designed to provide a differentlevel of protection for varying commercial or residential applications.For example, hospitals and morgues, which handle large quantities ofhazardous wastes on a daily basis, require much heavier-duty backflowpreventers than a residential irrigation system. Several backflowprevention devices are available at watts.com/backflowprevention.

One phenomenon of some backflow prevention devices is the occasionalejection of some water or even the release of a significant amount ofwater. For example, a pressure fluctuation where a building pressurerises above the main pressure may cause momentary backflow that isreleased by the backflow prevention device. In another more dramaticcircumstance, the main pressure drop may be sustained, which couldresult in the water within a building being dumped to drain to preventbackflow contamination. For a tall building, this could be a significantamount of water at a large flow rate.

To accommodate water released from backflow prevention devices, systemsare usually designed so that the released water goes to drain. However,the drain system may be insufficient, blocked or even non-existent.Often, the drain system has an inlet funnel for catching the releasedwater. Such inlet funnels usually maintain an air gap to the watersystem, again for preventing cross-connection and, thereby, a potentialsource of contamination.

SUMMARY OF THE INVENTION

In view of the above, a need exists for a leak detector that couples tothe water system for detecting small and large releases of backflow. Thepresent disclosure is directed to a leak detector assembly for use witha backflow prevention device including a housing defining a passagewayfor receiving a fluid. A flap assembly couples to the housing forgenerating a low flow error signal indicating minimal fluid passingthrough the passageway and a fully actuated error signal indicatingsignificant fluid passing through the passageway. The flap assemblyincludes a flap mounted in the passageway such that significant flow ofthe fluid moves the flap to generate the fully actuated error signal.The flap assembly also includes a sensing element on the flap todetermine a presence of the fluid without movement of the flap togenerate the low flow error signal based on a low flow of the fluid.

The leak detector assembly may also include a printed circuit board forprocessing at least one of the fully actuated error signal and the lowflow error signal. A main controller can connect to the printed circuitboard for providing communication of the signals and storing a date,time and duration of each signal. The communication may be wireless suchas through a wireless local area network, the Internet, cellularnetworks and the like. The communication may also be wired such as intoa LAN or the Internet by Ethernet cable and the like. In one embodiment,the flap assembly includes a magnet coupled to the flap for rotationtherewith and a fixed magnetic sensor such that the fully actuated errorsignal is generated based upon the magnet moving away from the fixedmagnetic sensor. One of the magnet and the fixed magnetic sensor ismechanically adjustable to adjust a trip level for the fully actuatederror signal. Typically, the flap is mounted for 90° of rotation in thehousing. The flap can also be mounted at an angle so that fluid does noteasily collect thereon. For example, the flap may be at a 45 angle withrespect to horizontal. The sensing element is preferably co-planarinter-digitated conductive traces connected to a printed circuit board.In one embodiment, an application specific printed circuit boardreceives at least one signal from the leak detector assembly, determinesa comparison of the at least one signal to a predetermined threshold,and generates an alarm based upon the comparison.

It should be appreciated that the subject technology can be implementedand utilized in numerous ways, including without limitation as aprocess, an apparatus, a system, a device, a method for applications nowknown and later developed. These and other unique features of the systemdisclosed herein will become more readily apparent from the followingdescription and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

So that those having ordinary skill in the art to which the disclosedtechnology appertains will more readily understand how to make and usethe same, reference may be had to the following drawings.

FIG. 1 is a schematic illustration of a leak detector assembly connectedto a portion of a building piping network in accordance with the subjectdisclosure.

FIG. 2 is a schematic illustration of a main controller in accordancewith the subject disclosure.

FIG. 3 is a perspective view of a leak detector assembly in accordancewith the subject disclosure.

FIGS. 4A and 4B are exploded views of a leak detector assembly inaccordance with the subject disclosure.

FIG. 5 is a partial cross-sectional view of a leak detector assembly inaccordance with the subject disclosure.

FIG. 6 is a partial cross-sectional view of another leak detectorassembly in accordance with the subject disclosure.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The subject technology overcomes many of the prior art problemsassociated with water discharge from backflow prevention devices. Theadvantages, and other features of the technology disclosed herein, willbecome more readily apparent to those having ordinary skill in the artfrom the following detailed description of certain preferred embodimentstaken in conjunction with the drawings which set forth representativeembodiments of the present technology and wherein like referencenumerals identify similar structural elements. Terms such as lower,upper, right and left are used in reference to the figures forconvenience and not meant in a limiting manner.

Referring now to FIG. 1, there is shown a schematic illustration of aleak detector assembly 100 connected to a portion of a building pipingnetwork 20. The piping network 20 has a backflow prevention assembly 22.The backflow prevention assembly 22 may be a double check detectorassembly, Model 007DCDA, available from Watts Water Technologies, Inc.at watts.com. A leak detector assembly 100 may couple to the backflowprevention assembly 22 or simply be placed below the backflow preventionassembly 22 in a location to capture fluid released by the backflowprevention assembly 22.

The leak detector assembly 100 generates signals indicating threedifferent conditions to a main controller 180. The three differentconditions are: “normal,” which indicates that the backflow preventiondevice 22 is not discharging water; “low flow error,” which indicatesthat the backflow prevention device 22 is discharging or has recentlydischarged a small amount of water; and “fully actuated error,” whichindicates that the backflow prevention device 22 is actively discharginga significant amount of water.

Referring now to FIG. 2, a schematic illustration of a main controller180 in accordance with the subject disclosure is shown. The maincontroller 180 may be hardwired to the leak detector assembly 100 asshown. However the communication may be wireless via a Bluetooth orsimilar wireless module 182. The incoming signals are processed andstored by a microprocessor 184 and memory 186. The main controller 180has an alarm module 188 for providing various alarms such as lightsand/or sounds as desired for the low flow and fully actuated errorconditions. The alarm module 188 may contain a light stalk and alarmhorn. The main controller 180 may also control operation of theassociated fluid system to address valve failure and prevent furtherleakage and/or flow as the case may be. In one embodiment, the maincontroller 180 contacts a service representative by email, text, orvoicemail to a telephone 185 (see FIG. 1) to inform the servicetechnician of the condition(s). The main controller 180 may be batteryoperated and/or connected to building power.

It is envisioned that data from the memory 186 can be downloaded togenerate reports indicating conditions that have been triggered (e.g.,low flow and fully actuated error conditions) along with the date andtime of such conditions. As such, performance data can be collected andstored in the memory 186 for analysis. The memory 186 can also storethreshold values. For example, the memory 186 can store time limits, acounter indicating the number of times that a signal was generated, andthe like. It is envisioned that an application specific printed circuitboard can encompass some or all of the functionality of the controller.The application specific printed circuit board can receive signals fromthe leak detector assembly, determine a comparison of the signals topredetermined thresholds and other information, and generate and/or sendone or more alarms based upon the comparison. The alarms can be aflashing light, sound, a text message and the like.

In one embodiment, the controller 180 determines if maintenance isneeded based upon the collected data. Preferably, the main controller180 provides notifications of status and maintenance using a wirelessmodule 182 to communicate with a network 183. The network 183 may be alocal area network or the like connected to the Internet. Thecommunication may be wired or wireless across any technological platformnow known and later developed. The notifications and maintenanceinformation can be provided directly to technicians such as by text to atechnician telephone 185 and/or to a company representative having amaintenance van 187, and the like.

Referring now to FIG. 3, a perspective view of the leak detectorassembly 100 is shown. The leak detector assembly 100 includes an upperinlet funnel 102 for capturing water discharged from the backflowprevention device. The inlet funnel 102 couples to a housing 104 thatdefines a passageway 106 through which the discharged water also passes.Typically, a lower end 108 of the housing 104 aligns with a system drain(not shown) so that discharged water passes into the drain.

In one embodiment, there are air gaps so that the inlet funnel 102 andlower end 108 do not contact the system plumbing. Alternatively, theinlet funnel 102 and/or the lower end 108 may be further connected to apiping system in a fluid tight manner for handling and removal of thedischarged water. The lower end 108 has inner threads 114 for suchconnection.

The housing 104 includes an electrical box 112 for receiving a printedcircuit board (pcb) assembly 140, which is a slightly alternativeconfiguration as compared to FIG. 1. The housing 104 has a centralportion 120 with a flapper assembly 170 partially mounted therein. Thecentral portion 120 is square in cross-section. The flapper assembly 170and the pcb assembly 140 are in electrical communication. In short,depending upon the position of the flapper assembly 170, the pcbassembly 140 generates the proper condition signal to be passed along tothe main controller 180, wherever it may be.

A cover 122 mounts on the housing 104 to protect the pcb assembly 140and the flapper assembly 170. The cover 122 may be clear,semi-transparent or opaque. In any case, the cover 122 defines a window124 so that the pcb assembly 140 may be seen. The cover 122 defines aplurality of mounting bores 126 that align with threaded shoulders 128on the housing 104 so that the cover 122 can be screwed to the housing104. The inlet funnel 102, housing 104 and cover 122 may all befabricated from the same or different materials. The materials may bemetal, plastic, ceramic and the like now known and later developed.

Referring now to FIGS. 4A and 4B, exploded views of the leak detectorassembly 100 are shown. The pcb assembly 140 includes a printed circuitboard (pcb) 142 mounted to the electrical box 112 with fasteners (notshown). The printed circuit board 142 has a plurality of integratedcircuit (IC) chips 144 and other electronic devices 146 mounted thereon.The IC chips 144 may accomplish the functionality of the microcontroller180 in whole or in part. The other electronic devices 146 may becapacitors, resistors, and like components necessary for the operationof the leak detector assembly 100 as described herein. In particular,the printed circuit board 142 has a yellow light emitting diode (LED)148 a and a red LED 148 b for visually indicating the low flow and fullyactuated error conditions, respectively. The pcb assembly 140 alsoincludes two batteries 150 that may power the pcb assembly 140 or simplyprovide battery backup.

Features 116 on the housing 104 allow the inlet funnel 102 to snap-fitto the housing 104. For additional security, the inlet funnel 102 mayform a slot 118 so that the inlet funnel 102 may also be screwed to thehousing 104. The flapper assembly 170 includes a square flap 172 mountedon a hinge post 174. The hinge post 174 rotatably mounts inside thecentral portion 120 of the housing 104 so that the flap 172 selectivelysubstantially blocks the passageway 106 in the normal position.Preferably, the flap 172 is spring biased into the normal position. Thehinge post 174 preferably has a flat surface for stably mounting theflap 172. Each end 176 of the hinge post is circular and sized to fit ina respective bore 130 formed in the housing 104. Each end 176 alsopreferably defines an annular ridge for receiving a locking ring (notshown) to retain the hinge post 174 rotationally mounted in the bores130. In another embodiment, a transverse bore and cotter pin are usedinstead of an annular ridge and locking ring.

The flap 172 also includes a plurality of conductive traces 178 on anupper side. The conductive traces 178 electrically connect to the pcbassembly 140 to generate the low flow error signal. The conductivetraces 178 may be co-planer inter-digitated fingers of an electricallyconductive material such as copper. When water contacts the traces 178,the capacitance changes so that variation in capacitance across thetraces 178 may be used to determine if the traces 178 are wet. Anexample of such traces is shown in U.S. Pat. No. 7,753,071 issued onJul. 13, 2010 to J. Wood, which is incorporated herein by reference.Additional circuitry for the operation of the traces 178 may be locatedon the lower side of the flap 172. However, it is preferred that suchcircuitry is mounted on the printed circuit board 142. In anotherembodiment, a humidity sensor or other type of sensor is mounted on theflap 172 to determine relevant fluid flow parameters.

Referring additionally to FIG. 5, a partial cross-sectional view of theassembled leak detector assembly 100 in the normal position is shown. Inoperation, when the backflow prevention device burps or leaks a smallamount of water, the flap 172 does not move because of the biasing butthe flap 172 does become wet. The moisture causes a change incapacitance that is processed by the pcb assembly 140 and maincontroller 180 so that the yellow LED 148 a lights and the low flowerror signal is generated to sound an alarm and/or forwarded asnecessary. It is envisioned that service personnel may simply track tolow flow error signals to determine system reliability and the like butnot take further action if only the low flow error signal is generated.

The flapper assembly 170 also includes a sensor 188 to generate thefully actuated error signal. The sensor 188 threads into a sensor mount132 formed on the housing 104. The sensor mount 132 preferably is twospaced apart brackets 134. The fully actuated error signal of the sensor188 is carried to the pcb 142 and/or the main controller 180 by wires196. In one embodiment, the sensor 188 is a magnetic sensor thatgenerates the fully actuated error signal when a magnetic tip 190 of athreaded post 192 moves a certain distance away from the sensor 188.Preferably, the threaded post 192 and magnetic tip 190 are sized to passthrough at least one of the brackets 134 of the sensor mount 132 toallow a wide range of adjustment of the mechanical position.

When the magnetic tip 190 is adjacent the sensor 188, the sensor 188either generates no signal or a normal condition signal depending uponhow the pcb assembly 140 and main controller 180 logic is programmed.The magnetic tip 190 moves by virtue of the post 192 being mounted on arotating arm 194. The arm 194 is mounted on the hinge post 174 so thatwhen the flap 172 and the hinge post 174 rotate, the magnetic tip 190moves away from the sensor 188. It is envisioned that the arrangement ofthe sensor and magnet could be reversed however, it is typically moreefficient to have the sensor, which requires wiring, be the stationarycomponent.

Preferably, the post 192 threads into the arm 194 so that position ofthe post 192 can be adjusted to set the trip level of the flap 172. Theopposing end 198 of the post 192 may be a hex head or the like so thatthe post 192 can be adjusted with a socket, wrench, allen wrench orscrewdriver. If necessary, one or more nuts (not shown) can be threadedonto the post 192 to lock the post in position on the arm 194. Dependingupon the desired setting, the post 192 can even be moved so that theflap 172 is angled with respect to the axis of the housing 104 (i.e.,the direction of fluid flow).

In operation, when the backflow prevention device discharges a largeamount of water, the water overcomes the bias of the flap 172, which isforced to rotate approximately 90° in the central portion 120 so thatthe water may flow through the passageway 106. This movement of the flap172 and, thereby, the hinge post 174 rotates the arm 194 approximately90° so that the magnetic tip also moves 90° away from the sensor 188. Asa result, the sensor 188 switches state, the pcb assembly 140 and themain controller 180 recognize the change so that the red LED 148 blights and the fully actuated error signal is generated for appropriateaction. In effect, the flap 172 does double duty because the conductivetraces 178 thereon lead to the low flow error signal and movement of theflap 172 generates the fully actuated error signal.

Referring now to FIG. 6, a partial cross-sectional view of a secondembodiment of a leak detector assembly 200 in accordance with thesubject technology is shown. Similar elements to those described inconnection with above-described embodiments are indicated with the likereference numbers but part of the 200 series instead of 100 series ofnumbers. Many elements are essentially the same as those of theforegoing embodiments and, thus, are not further described herein. Theprimary difference between the leak detector assembly 200 and the leakdetector assembly 100 is the lack of an inlet funnel. Instead, the leakdetector assembly 200 has a threaded top portion 203 for couplingdirectly to a backflow prevention device (not shown) effectivelybecoming a combination leak detector and backflow prevention device. Aninlet funnel may still be present as part of the drain system as isoften the case.

The leak detector assembly 200 is shown in the normal position. Althoughthe flap 272 maintains the normal position, as noted above, a smallamount of moisture discharge from the backflow prevention device will besensed by the traces 278 and activate the low flow error signal. Again,as significant flow overcomes the normal position bias of the flap 272,the flap 272 rotates 90° to clear flow in the passageway 206. As aresult, the magnetic tip 290 of the post 292 rotates away from thesensor 288 so that the fully actuated error signal is generated.

It is also envisioned that an inlet funnel could threadably engage thetop portion of the housing 204. In an alternative embodiment, the inletfunnel is not only shaped to collect discharged water but gently directthe flow onto the flap. For example, the inlet funnel may includehelical grooves that direct the fluid flow around the housing axisbefore reaching the flap. Additionally, a screen or shower head deviceabove the flap may disburse the energy of the fluid in order to elevatethe required flow for full actuation. The inlet funnel may also includean absorptive material so that fluid discharge needs to be in excess ofthe absorption capacity before the low flow error signal is generated.In one embodiment, the main controller is able to reset operation (e.g.,bleeding and clearing errors etc.) in the event of a low flow errorsignal.

In another embodiment, the normal or rest position of the flapperassembly is varied according to user preference. For example, in thenormal position, the flap can be at 45° with respect to the horizon. Asa result, the flap will shed drips effectively so that moisture does notpuddle on the flap. In another embodiment, the flap 372 rests at 30° tothe horizon.

It will be appreciated by those of ordinary skill in the pertinent artthat the functions of several elements may, in alternative embodiments,be carried out by fewer elements, or a single element. Similarly, insome embodiments, any functional element may perform fewer, ordifferent, operations than those described with respect to theillustrated embodiment. Also, functional elements (e.g., modules,databases, interfaces, printed circuit boards, main controllers,computers, arms, couplings and the like) shown as distinct for purposesof illustration may be incorporated within other functional elements ina particular implementation. For example, the main controller may beincorporated into the printed circuit board, logic programmed on memoryfor execution by a processor may be hard wired in a circuit, and thelike.

Further, although the subject technology has been described with respectto the field of water systems, it is envisioned that the subjecttechnology would be equally applicable to other fields and applicationssuch as chemical systems with gas or liquid. The subject technology alsohas broad application in the field of water systems. For example, thesubject technology may be utilized with backflow prevention assemblies,relief valve discharge assemblies, actual cash value (ACV) floorprotection sensing technology, water quality products, intelligentdrains that monitor plugging, and the like.

While the subject technology has been described with respect topreferred embodiments, those skilled in the art will readily appreciatethat various changes and/or modifications can be made to the subjecttechnology without departing from the spirit or scope of the inventionas defined by the appended claims. For example, each claim may dependfrom any or all claims in a multiple dependent manner even though suchhas not been originally claimed.

What is claimed is:
 1. A leak detector assembly comprising: a housingdefining a passageway for receiving a fluid; and a flap assembly coupledto the housing, the flap assembly including: a first post, a flap, arotating arm, a second post, a first flow sensor, and a second flowsensor, wherein the flap is mounted to the first post, the second postis connected to the first post by the rotating arm, the first flowsensor is configured to detect a low flow of fluid from the passagewaythrough the flap and generate a low flow error signal, and the secondflow sensor is configured to detect a high flow of fluid from thepassageway through the flap and generate a high flow error signal. 2.The leak detector assembly of claim 1, further comprising a printedcircuit board for processing at least one of the high flow error signaland the low flow error signal.
 3. The leak detector assembly of claim 1,further comprising a main controller connected to the flap assembly forproviding wireless communication of the low flow and high flow errorsignals.
 4. The leak detector assembly of claim 1, further comprising amain controller connected to the flap assembly for storing a date, timeand duration of each of the low flow and high flow error signals.
 5. Theleak detector assembly of claim 1, wherein the flap assembly furtherincludes: a magnet coupled to the second post; and a third post, whereinthe second flow sensor is a fixed magnetic sensor located on the thirdpost and configured to generate the high flow error signal based uponthe magnet on the second post moving away from the fixed magnetic sensoron the third post.
 6. The leak detector assembly of claim 5, wherein oneof the magnet and the fixed magnetic sensor is mechanically adjustableto adjust a set point for the high flow error signal.
 7. The leakdetector assembly of claim 1, wherein the first flow sensor includes asensing element on the flap that is co-planar inter-digitated conductivetraces connected to a printed circuit board.
 8. The leak detectorassembly of claim 1, wherein the flap is mounted on the first post toallow 90° of rotation in the housing.
 9. The leak detector assembly ofclaim 1, wherein the flap is mounted on the first post substantiallyperpendicular to the passageway when neither the low flow nor high flowerror signals are activated.
 10. The leak detector assembly of claim 1,wherein the flap is mounted on the first post at an angle of 45° withrespect to an axis of the passageway.
 11. The leak detector assembly ofclaim 1, wherein the flap is mounted on the first post at an angle of30° with respect to an axis of the passageway.
 12. The leak detectorassembly of claim 1, further comprising a screen in the passagewayupstream of the flap for disbursing energy of the fluid.
 13. The leakdetector assembly of claim 1, further comprising an absorptive materialin the passageway upstream of the flap.
 14. The leak detector assemblyof claim 1, wherein the rotating arm and the second post are positionedon an exterior surface of the housing.
 15. The leak detector assembly ofclaim 5, wherein the third post is positioned on an exterior surface ofthe housing proximate to the second post.
 16. A leak detector assemblycomprising: a housing defining a passageway for receiving a fluid; and aflap assembly coupled to the housing, the flap assembly including: aflap mounted for rotation so that the fluid in the passageway isdirected to the flap; a first flow sensor on the flap for generating alow flow error signal without movement of the flap when a low flow ofthe fluid from the passageway wets the first flow sensor; and a secondflow sensor mounted for rotation with the flap for generating a highflow error signal based on movement of the flap as a result of a highflow of the fluid from the passageway hitting the flap.